This is the third phase of a longitudinal study of the psychosocial development of aggressive behavior. Subjects first seen in 1960 included the entire third grade population (N equals 875) of a semi-rural county in New York State. They were seen in the classroom for a series of group tests and questionnaires. Personal interviews were conducted with 85% of their mothers and 71% of their fathers to determine learning conditions in the home which would relate to aggression of children in school as rated by peers. In 1970 interviews were held with 427 of the original subjects; peer ratings were repeated and, along with other measures, self-ratings of aggressive behavior and the MMPI were administered. Arrest records and state hospital admissions statistics were also employed. Among the best predictors to aggression after 10 years were violence of preferred television programs at age eight, social mobility orientation of parents, and evidence of the internalization of society's standard of behavior. Findings have been reported extensively. A third phase is now planned in which it is expected that 300 of the original subjects will be reinterviewed as well as their spouses and any children they might have between ages six and ten. Arrest data and state hospital data will again be sought. Measures of psychopathology as well as interpersonal skills, vocational, intellectual and social competence and television habits will be related to past and current aggression and early socialization data. Longitudinal data from the three different phases will be analyzed to test causal hypotheses. Intergenerational effects will be of interest.